next up previous contents
Next: IRAF startup Up: Afternoon activities Previous: Mounting CCD filters

Biases and dome flats

You can take bias frames (dome lights off!!) with the commands
          SYS> bias
          SYS> multbias 5
where the first command does only one bias exposure, and the second executes a series of 5 bias exposures.

If you want to make dome flats, turn on the tungsten lamps on the telescope top ring with the buttons on the telescope console in the control room. Turn on the oil pumps and telescope (see Section 6, Twilight activities), and leave it in Engineering mode. You don't have to zeroset the encoders. Then manually point the telescope to a part of the dome that gives good reflected illumination of the telescope aperture, using the push buttons on the console. Open the mirror covers with the button on the console.

Make sure that the JAG light path is towards the CCD and not to the TV

          SYS> tv off
You can take dome flats of 10 seconds with the commands
          SYS> flat 10 "Dome flat"
          SYS> multflat 5 10 "Dome flat"
To change the filter position use
          SYS> filter V
          SYS> filter R
with arguments according to what you defined in the ICS filter database.